I have done 1 coding jam in the past, last year i attended toJam(72 hours to build a game based on a particular theme).
here's some things i took away:
1. Make sure your entire team is able to contribute(one of our team members simply should not have been their.)
2. Do your best to have a design in mind. (and make sure every team member is clear on what you/they are doing)
3. Do not allow feature creep to affect you, be very clear on what you want to achieve before going there.(This one is incredibly important for your time-scale.)
4. Know your limits, understand what you are able to do, 24 hours is very little time, and be vocal if you have any sort of problems.
5. Don't include people that won't be able to contribute(in our project, sound was simply the last thing to get around to, and unfortunately the team member that was tasked with audio wasn't able to do anything.)
6. Be very vocal if something is not going to work, if you can tell it'll take to long to implement it, cross it off your list right their.
A few of these points can be taken with a grain of salt, depending on how serious you want to take this. (i.e 1 and 5 can be ignored if you just care about having a good time.)
Personally, I was lead programmer(but not team lead) for a team of five, we suffered from feature creep(something i should have been more vocal about, when you are 2 days in, and someone says "Hey, let's add that!", you should say "No."). The person i was doing this with(our team lead), was too interested in entertaining everyone's ideas, and the game became too bloated to complete in our time-frame.
We had 2 programmers, an artist, and a sound guy, and the last guy simply should not have been their. (He was tasked with making the levels, but wasn't able to learn the level editor he was given, and the levels suffered greatly because of this(practically ignoring some of the mechanics we had built into the game, it became just a generic platformer.)
Their were so many problems(and a ton of stress), that it put me off from doing anymore of these jams.
Edited by slicer4ever, 05 March 2013 - 10:34 AM.